On the outskirts of Tokyo, behind a small government building, underneath a soccer field and skateboard park, sits a remarkable feat of engineering. It’s an example of how Japan’s capital, which lies in a region at high risk from flooding and tropical cyclones, is trying to figure out how to contain the elements to protect its 13 million inhabitants.

‘Underground Parthenon’

Built between 1993 and 2006 at a cost of nearly $3 billion, the Water Discharge Tunnel is far more impressive than its name suggests. Winding down a series of stairs, you soon come upon a massive hall, resembling an underground Parthenon, or a scene out of a science fiction film.

The initial water tank stretches more than 320 feet in length and towers higher than a five-story building. When you add it all up, the complex features five massive shafts, or tanks, that are able to move water along a tunnel that stretches nearly four miles.

‘Incredible drain system’

In this area of Saitama prefecture, heavy rains would often flood the Naka River Basin. But now, that valuable farmland has an incredible drain system sitting below. When the tanks and tunnel fill, engineers are able to turn on the heart of the system, which is a series of four turbines powered by jet engines similar to those used in a Boeing 737 airplane. The turbines are then able to rapidly funnel floodwaters to the nearby Edo River.

The engineers here are the first to point out that their system, while remarkable, is meant to deal with heavy rains — and that it would struggle to cope with a Sandy-type storm surge.

Do you find Tokyo’s Water Discharge Tunnel an amazing engineering feat? Feel free to share your feedback with us!

European officials reacted with fury Sunday to a report that the U.S. National Security Agency spied on EU offices. The European Union warned that if the report is accurate, it will have tremendous repercussions.

‘Electronic eavesdropping operation’

The outrage from European officials over the weekend was the latest fallout since Edward Snowden, a former National Security Agency computer contractor, started spilling details of U.S. surveillance programs to reporters earlier this month.

Citing information from secret documents obtained by Snowden, the German news magazine Der Spiegel reported Sunday that several U.S. spying operations targeted European Union leaders. Der Spiegel said it had “in part seen” documents from Snowden that describe how the National Security Agency bugged EU officials’ Washington and New York offices and conducted an “electronic eavesdropping operation” that tapped into a EU building in Brussels, Belgium.

‘Seeking asylum’

The Guardian newspaper reported that one NSA document leaked by Snowden describes 38 embassies and missions as “targets” and details surveillance methods that include planting bugs in communications equipment and collecting transmissions with specialized antennae. Targets included France, Italy, Greece, Japan, Mexico, South Korea, India and Turkey, according to The Guardian.

Snowden has revealed himself as the source of documents outlining a massive effort by the NSA to track cell phone calls and monitor the e-mail and Internet traffic of virtually all Americans. Critics slam him as a traitor. Supporters hail him as a hero. Now Snowden, who faces espionage charges in the United States, is in Russia and seeking asylum from Ecuador.

Do you believe the NSA was really spying on EU offices? What impact could this report have on the relations between the U.S. and Europe?